jQuery.fn.extend({
	autoHeight: function(){
		return this.each(function(){
			var $this = jQuery(this);
			if( !$this.attr('_initAdjustHeight') ){
				$this.attr('_initAdjustHeight', $this.outerHeight());
			}
			_adjustH(this).on('input', function(){
				_adjustH(this);
			});
		});
		function _adjustH(elem){
			var $obj = jQuery(elem);
			return $obj.css({height: $obj.attr('_initAdjustHeight'), 'overflow-y': 'hidden'})
					.height( elem.scrollHeight );
		}
	}
});
